History of F-Heads

1903-11
The Harley Davidson F-Head was so called because of its “Inlet over Exhaust” engine configuration, also termed “pocket valve”, this being very much the standard of the day. The F-Head models of the first decade were very much functional, ‘common sense’ motor cycles with larger, more powerful engines than those of their competitors. In 1911 their first V-twin was successfully introduced but this was still limited to direct belt drive with a tensioner to effect and control drive. Advanced as they were for their time, when measured in terms of today’s riding conditions, these first decade machines with their bicycle type frame configurations and direct belt drives are extremely difficult to operate, even for experienced Pioneer era machine riders.  For this reason these machines are seldom seen on the road and generally (but not always) languish in museums and heated living rooms.
1912-13

This all changed in 1912 when the new season saw some major engineering developments which have made these second decade models much more useable in modern traffic conditions. These improvements included a sloping edge to the rear of the frame and a lower saddle height which improved stability and also a sprung seat post suspension system which made the ride far smoother. The introduction of chain-drive and a free-wheel clutch greatly improved the riding experience and wheel skirts helped keep muck off the engine and rider. This is the period of which we are concerned as these machines are the earliest which can practicably be operated in today’s Pioneer and Horseless events. 
1914-16

The 1914 models were visibly more substantial and robust.  The fenders were widened, footboards were added as standard and both the brake and clutch were operable by foot pedals.  A two-speed hub was introduced which added significantly to the speed and a dual action rear brake was added for additional safety. In 1915 a three speed transmission was introduced, albeit still with the pedal starting system and an electrical system for lighting and accessories. In 1916 a more conventional three speed transmissions with a rear stroke (kick) starter was introduced and the appearance was further improved with newly styled and more rounded tanks, wider forks and even wider fenders with integral braces. Thereafter, the basic design of the F-Head having been established, it was further refined and improved through to 1928 until the introduction of the side-valve.